The present invention generally relates to a portable information terminal apparatus and a display scroll method. More particularly, the present invention relates to a portable information terminal apparatus, especially such a portable information terminal apparatus for executing signal communication by radio wave such as a pager that, when the terminal apparatus receives radio waves from a remote radio base station, the terminal apparatus confirms that the received signal is addressed to itself, notifies a user of the termination call by sound, light, or mechanical vibration, displays the received information on the incorporated image display device, and scrolls a display screen based on the commands inputted by the user. The present invention also relates to a method of scrolling the display screen.
Portable information terminal apparatuses having various constitutions and providing various capabilities and functioning as communication network terminals have been put in practical use to satisfy the recent wide-range and drastically expanding demands in information communication fields.
One example of such portable information terminal apparatuses is a pager commonly used for signal reception by radio. The pager in its infancy was a terminal apparatus that beeps upon reception of a calling signal from a radio base station. In operation, a caller sends a calling signal from a wire telephone through radio to the user carrying the pager on the road. Upon reception of the calling signal, the user makes a call to the caller from a nearby wire telephone.
Recently, pagers have been developed and are in extensive use that have capabilities of receiving not only a simple calling signal, but also a signal carrying various information from a radio base station and displaying the received information on the liquid crystal display monitor as a message.
Further, various other features are provided for today's paging devices. One common feature is the use of both beeping and mechanical vibration for notifying the user of calling signal termination. The mechanical vibration is activated instead of beeping in an environment where a surrounding noise level is so high that the user cannot hear beeping or where beeping may cause disturbance if used in a theater or a lecture room for example. The user can select between the beeping and vibrating modes by manually setting the selection through the data input device of the pager.
The above-mentioned portable information terminal apparatuses have data input devices through which the user specifies operating conditions. For such data input devices, key-type or button-type is used on the related-art portable information terminal apparatuses.
However, the key-type or button-type data input devices are not always suitable for a continuous data input operation. In addition, because these devices each provide a single function, the number of data input devices increases with the above-mentioned functional expansion of portable information terminal apparatuses, thereby making the operation of these apparatuses complicated and causing a bottleneck in miniaturization of these apparatuses.
To overcome this problem, a data input device of rotary type and a rotary input device with a push switch integrated have come to be used instead of the above-mentioned data input devices of key-type or a button-type. These data input devices are commercialized as a jog dial and rotary encoder for example. With these devices, a rotary disc knob of each device is rotated clockwise (to the right) or counterclockwise (to the left) to easily provide a control signal, thereby facilitating an operation for generating a plurality of input signals in a unit time. In addition, two lines of input signals can be provided from one rotary input device, thereby saving the space to be occupied by data input devices.
Meanwhile, when displaying message information (a message statement) carried by a received signal onto the image display device, the number of lines displayed on the image display device is limited. Therefore, the message information can be displayed only in the maximum number of display lines (four lines for example). If a received message consists of many lines (four or more lines for example) of information, the screen of the image display device must be scrolled.
Generally, display scrolling is made up or down, replacing the currently displayed lines with updated new lines. Preferably, scrolling may be manually performed by the user for specifying scroll count, direction, and speed.
Especially, it is desirable to provide a constitution that allows the user to input a plurality of scroll commands in a relatively short time for quick confirmation of a message statement consisting of many lines. To realize this constitution, a high-speed scroll capability must be provided.
Obviously, the above-mentioned rotary input device, which allows the user to quickly perform clockwise and counterclockwise rotary operations to generate many input signals in a unit time, can be suitably applied to the scroll command inputting, thus at least satisfying the above-mentioned requirement of quick command input operations.
However, the above-mentioned in a related art constitution presents a problem that, while the above-mentioned rotary input devices allow the user to perform a plurality of scroll command input operations in a short time, the scroll processing capability of the portable information terminal apparatuses having these devices is sometimes incapable of following the speed of the input operations.
For example, assume that several scroll command input operations are consecutively performed in a short time through the data input device to effect a high-speed scroll operation on the display screen. If eight input operations are consecutively performed, eight scroll command signals are generated because one operation causes one scroll command signal. As a result, eight single-line-feed scroll operations are consecutively performed. According to the related art constitution, one scroll operation replaces the display image by one line, furthermore the entire display screen is updated each time and the updated screen is displayed at every scroll operation done.
Consequently, if the display updating speed of the liquid crystal panel of the image display device for example or the processing speed of peripheral circuits cannot promptly follow the high-speed scroll command input operations or the CPU of the portable information terminal apparatus is not powerful enough to promptly follow the scroll command input operations, every scroll operation, especially every display updating operation takes time to cause a sense of disagreement between the scroll command input operation and the scroll processing, thereby degrading the ease of operation of portable information terminal apparatuses.